“…Although nerve-induced contractions of the rat bladder in vitro are antagonized by noradrenaline or isoprenaline (Carpenter, 1970), it is doubtful whether the sympathetic innervation suppresses bladder contractility associated with micturition in the rat; adrenergic fibres do not seem to influence intravesical pressure at physiological stimulus rates (Elmer, 1978). Also in other species, the urinary bladder may contract during stimulation of the hypogastric nerves (Sigg & Sigg, 1964;Shaffer, Stephenson & Thomas, 1979). Bladder contractions mediated by a-adrenoceptors would appear to be restricted to the trigone at the base of the organ (Raezer, Wein, Jacobowitz & Corriere, 1973) and produce small elevations in pressure.…”